The present invention is directed to bicycle shift control devices and, more particularly, to a grip for a twist-grip shift control device which conforms more closely to a rider's hand.
Twist-grip shift control devices are sometimes used to control various types of bicycle transmissions. Example such devices are disclosed in JP 44-26571; U.S. Pat. No. 3,633,437; U.S. Pat. No. 4,900,291 and U.S. Pat. No. 5,197,927. Such devices typically include a generally annular rotatable member that is mounted around the bicycle handlebar coaxially with the handlebar axis, wherein rotation of the rotatable member with the palm of the hand controls the pulling and releasing of the transmission control cable.
For reliable operation of twist-grip shift control devices, it is desirable to have adequate traction between the palm of the hand and the rotatable member. U.S. Pat. No. 5,564,316 and U.S. Pat. No. 5,584,213 discuss the use of nubs and elongated ribs on a flexible cover to increase the traction between the hand and the rotatable member. However, while such nubs and ribs may help improve traction, they also tend to jam into the rider's hand, thus creating pain and fatigue.